Mutagenic effect of epichlorohydrin. II. Analysis of chromosomal aberrations in lymphocytes of persons occupationally exposed to epichlorohydrin.

A prospective cytogenetic study was conducted in 35 workers occupationally exposed to epichlorohydrin (ECHH). Blood samples for cytogenetic analysis were collected before the exposure (to serve as a control) and after the first and second years of ECHH exposure; the cultivation time was 56--58 h. Four slides from each worker were prepared, coded and two of them separately analysed in two collaborating cytogenetic laboratories. About 50 cells were analysed on each slide, giving a total 16,674 scored cells. The percentage of cells with chromosomal aberrations in blood samples of workers was 1.37 before exposure, 1.91 after the first year and 2.69 after the second year of exposure. The difference between percentages of aberrant cells before and after two years of occupational exposure was highly significant (P less than 0.0001). There was particularly observed an increase of chromatid and chomosomal breaks after exposure, simultaneously with an increased number of breaks per 100 cells. These results are concordant with previously reported cytogenetic data found in experiments with mammals and human cells in vitro.